Objective: To diagnose parasitic worms found in stomach while doing upper gastro-intestinal endoscopy in our patients. There have not been many studies in India which discuss about the presence and the type of parasitic worms present in stomach while doing upper gastro-intestinal endoscopy. Hence this present study was carried out to study about the presence and the type of parasitic worms present in stomach while doing upper gastro-intestinal endoscopy in our institute. Methods: A study of 707 patients who had undergone upper gastro-intestinal endoscopy for a period of two years and eight months from May 2009 to December 2011 was carried out in our institute. In each of the 707 patients, the stomach was carefully examined to find out the presence of parasitic worms. The results were found as given below. Results: Of the 707 patients, one patient was found to have hookworm in stomach instead of its usual site in duodenum while doing upper gastro-intestinal endoscopy. Conclusion: Hence upper gastro-intestinal endoscopy is a very useful investigation to diagnose parasitic infection like hookworm infection of stomach . Hence it is extremely important to carefully look for the presence of parasitic worms like hookworms in stomach while doing upper gastro-intestinal endoscopy.